Radioactivity in Foods Grown on Florida Phosphate Lands

This study involved radioactivity in foods grown on Florida phosphate lands. More than 90 land parcels in central Florida were identified and evaluated for potential food production. Over 100 food samples were collected from 62 of these land parcels and subjected to radioassay for isotopes of radium, uranium, and thorium. Corresponding soil samples were also collected and analyzed for radium-226 and pH.

Statistical analysis of the radium-226 data has shown that the average concentrations exhibited by foods grown on mined lands was significantly higher than the average concentrations exhibited by foods grown on unmined lands. Descriptive analyses of the other radionuclides support this conclusion. A hypothetical individual who obtains 100 percent of the foods sampled in this study from mined lands and the remainder of his diet from the general food pool is estimated to receive 4 mrem per year in committed effective dose equivalent from ingestion of the radionuclides reported in this study. This is 0.3 mrem (8 percent) per year more than a similar individual who obtains 100 percent of the food sampled in this study from unmined lands. These dose levels are quite low and are not considered to be a health hazard.